25999131561 has 8 divisors (see below), whose sum is σ = 37332086400. Its totient is φ = 15999465552.

The previous prime is 25999131523. The next prime is 25999131569. The reversal of 25999131561 is 16513199952.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25999131561 - 2²² = 25994937257 is a prime.

It is a super-3 number, since 3×25999131561³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (25999131569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333322161 + ... + 333322238.

It is an arithmetic number, because the mean of its divisors is an integer number (4666510800).

Almost surely, 2^25999131561 is an apocalyptic number.

It is an amenable number.

25999131561 is a deficient number, since it is larger than the sum of its proper divisors (11332954839).

25999131561 is a wasteful number, since it uses less digits than its factorization.

25999131561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666644415.

The product of its digits is 656100, while the sum is 51.

The spelling of 25999131561 in words is "twenty-five billion, nine hundred ninety-nine million, one hundred thirty-one thousand, five hundred sixty-one".